Leuco sulfuric acid esters of anthraquinone-azo-dyestuffs



' chloroanthraquinone United States Patent LEUCO SULFURIC ACID ESTERS OF ANTHRA- QUlNONE-AZO-DYESTUFFS Eduard Besler and Otto Braunsdorf, Frankfurt am Main,

Germany, assignors to Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius und Bruning, Frankfurt am Main, Hochst, Germany No Drawing. Application May 29, 1952, Serial No. 290,822

esters of anthraquinone-azo-dyestutts; more particularly it relates to dyestuffs of the following general formula:

OHa

where X represents hydrogen or halogen and R represents a radical ofthe benzene series.

It is known to convert azo-dyestuffs from diazotized l-amino-anthraquinone or its halogen substitution products and acetoacetylamino-benzenes into their leuco sulfuric acid esters by treating them with chlorosulfonic acid or other agents yielding sulfuric anhydride in the presence of a tertiary base and of a metal (German Patents Nos. 539,115, 723,132, 724,273 and 729,301). The dyestuffs so obtained are all derived from l-aminoanthraquinone or its halogen derivatives which, however, are known for their special position in the chemistry of anthraquinones since, contrary to the isomeric Z-aminoanthraquinones, a great number of technically useful dyestuffs are derived therefrom and put on the market.

Now, We have found that valuable leuco sulfuric acid esters of anthraquinone-azo-dyestuffs are obtained by treating the azo-dyestufis from diazotized 2-aminoanthraquinones and acetoacetylamino-benzenes with ch-lorosulfonic acid or other agents yielding sulfuric anhydride in the presence of a tertiary base and of a metal. The new leuco sulfuric acid esters yield yellow dyeings of a good dischargeability and of properties of fastness which entirely meet with the demands of the practice. The dyestuffs obtained by using acetoacetylaminobenzene as coupling component are distinguished by a very clear greenish yellow shade of fastness properties which could hitherto not be produced in the series of the leuco sulfuric acid esters. The dyestuffs of the present invention, therefore, constitute a valuable advance in the dyeing industry.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto; the parts being by weight:

Example 1 80 parts of chlorosulfonic acid are slowly added drop by drop while cooling to 320 parts of a pyridine fraction boiling at a temperature of 125 C.126 C. Into the mixture so obtained there is introduced at 35 C. a mixture of 30 parts of iron powder and 40 parts of the azodyestulf prepared by coupling diazotized 2-amino-3- with acetoacetylamino benzene. The mixture is then slowly heated to 50 C. and stirred at this temperature, until the esterificationis complete up 2,775,583 Patented Dec. 25, 1956 CH3 OS OsNa I '00 N=N(IJH C0 C1 1 OSOaNa The leuco sulfuric acid ester so obtained yields on cotton, rayon or staple fiber from viscose, when developed in the usual manner with acid oxidizing agents, vivid greenish yellow shades which are distinguished by very good fastness properties.

By using the 2-amino-3-bromoanthraquinone as diazocomponent instead of 2-amino-B-chlozroanthraquinone, =a dyestuff of similar properties is obtained.

Example 2 A mixture of parts of an azo-dyestuif obtained by coupling diazotized 2-amino3-chloroanthraquinone with acetoacetylamino-benzene and 60 parts of iron powder is introduced at a temperature of 35 C. to 40 C. into an esterification mixture prepared from 640 parts of 'alpha-picoline and 160 parts of chlorosulfonic acid at a temperature of 20 C. to 25 C. t t p The temperature of the reaction mixture is raised to 44 C. to 45 C. by external heating and then stirred at this temperature, until a clear red solution is obtained. This solution is poured, while stirring, on 2000 parts of ice and 20 parts of kieselguhr, whereby at first a dark red solution is obtained from which, after further stirring, the alpha-picoline salt of the leuco sulfuric acid ester separates in the form of small orange crystals. After allowing to stand for several hours, the picoline salt is filtered with suction, pressed and, in order to remove the picoline, dissolved in 4000 parts of a sodium carbonate solution of 4 percent strength and distilled under reduced pressure. After clarifying the ester solution the sodium salt of the leuco sulfuric acid ester is salted out by adding 10 percent of sodium chloride at a temperature of 80 C. to C. It separates in the form of reddish yellow flakes which are filtered with suction after cooling. The ester is stabilized by addition 80 parts of the azo-dyestufi obtained from diazotized 2- amino-3-chloroanthraquinone and 1-acetoacetylarnino-2' methoxy-benzene are mixed with 60 parts of iron powder and then introduced into an esterification mixture prepared from 640 parts of alpha-picoline and 160 parts of chlorosulfonic acid andstirred. The temperature of the reactionmixture is raised to 50 C. and the mixture is stirred at this temperature until the esterification is complete. The reaction mixture is then poured into 4000 parts of a sodium carbonate solution of 5 percent Strength and the picoline is removed by distillation under reduced pressure. The clarified ester solution is salted out by adding sodium chloride. The sodium salt of the leuco sulfuric acid ester forms a reddish yellow, flaky mass; it is filtered with suction and stabilized by pasting it with small quantities of water and sodium carbonate.

The leuco sulfuric acid ester so obtained yields on cotton, rayon or staple fiber from viscose reddish yellow dyeings and prints which are distinguished by good fastness properties. Y

1 Example 4 At a temperature of 20 C. to 25 C. an este-rification mixture is prepared from 640 parts of a pyridine fraction boiling at a temperature of 125 C. to 130 C. and 160 parts of chlorosulfonic acid. The whole is heated to 35 C. and at this temperature there is introduced rather quickly a mixture of 60 parts of iron powder and 80 parts of the azo-dyestuff obtained from diazotized 2- aminoanthraquinone and acetoacetyiamino-beuzene. The reaction mixture is then raised to a temperature of 45 C., it gradually assumes a reddish coloration and the dyestufi begins'to dissolve. Before a complete solution is obtained brassy yellow, bright, small crystals, probably of a pyridine salt of the leuco sulfuric acid ester, separate. The mixture is then stirred at 45 C., until the esterification is complete. The reaction mass is then poured on 2000 parts of ice to which 20 parts of kieselguhr have been added while stirring, whereby the pyridine salt separates in ochre yellow small crystals. After standing for some time, the crystals are filtered with suction, pressed and the press cake is introduced, while stirring, into 4000 parts of a sodium carbonate solution of 4 percent strength. The pyridine is distilled under reduced pressure from the solution at a temperature of 35 C. to 40 C. When the distillation is finished, 20 parts of decolorizing carbon are added to the ester solution'which is then heated to a temperature of 70 C. to 80 C., while stirring, clarified and the sodium salt of the leuco sulfuric acid ester is separated by gradually adding 10 percent of sodium chloride. The light yellow flaky precipitate so obtained is filtered with suction, after cooling to room temperature. By adding 2 percent of sodium carbonate the dyestuff paste is stabilized.

The leuco sulfuric acid ester obtained yields, when printed in the usual manner on cotton, rayon and staple fiber from viscose and developed with an acid oxidizing agent, vivid clear yellow shades which are distinguished by very good fastness properties. The dyestuif corresponds to the following formula:

OSOaNa l l OSOaNa Example :dyestufi canJnQ longer be detected. When this is the case, the brown-red solution is stirred into 2000 parts of a sodium carbonate solution of 6 percent strength and the pyridine is removed from the mixture by distillation under reduced pressure at about 40 C. The ester solution is freed from ferruginous mud and contaminations by filtration and the sodium salt of the leuco sulfuric acid ester is salted out from the clarified red-yellow solution by gradually adding 15 percent of sodium chloride. After allowing to stand for several hours, the precipitate is filtered with suction and made into a paste by adding small quantities of water and sodium carbonate.

The leuco sulfuric acid ester-soobtained yields, when printed in the usual manner on cotton, rayon or staple fiber from viscose and developed with an acid oxidizing agent, reddish-yellow prints of very good fastness properties.

By replacing the azo dyestufis'used in the preceding examples by the products obtained by-coupling diazotized Z-aminoanthroquinones with other acetoacetylamino-benzenes, such as 1 acetoacetylamino 2 chlorobenzene, 1- acetoacetyla-mino-Z.S-dichlorobenzene, 1 acetoacetylamino 2 methoxy-S-chlorobenzene, 1 acetoacetylamino-4- methylbenzene, 1 -acetoacetylarnino-Z-methoxy-4-bromobenzene, 1-acetoacetylamino 2.4-dirnethoxybenzene, 1- acetoacetylamino 2.5 dimethoxybenzene, l-acetoacetylamino-2.5-dimethoxy-4chlorobenzene, 1 acetoacetylamino-2-methoxy-4-benzoylamino-S-chlorobenzene, 1 acetoacetylamino-2-methyl-4.S-dichlorobenzene, l-acetoacetyL amino 2 methyl-5-methoxy-4-bromobenzene, l acetoacetylamino-3-methoxy 6 chlorobenzene, and 1 acetoacetylalrnin0-2.5-diethoxy-44bromobenzene, leuco sulfuric acid esters are obtained which are easily soluble in water and yield when dyed or printed according to the method usually applied with dyestuffs of this class, yellow shades of good fastness properties.

We claim:

1. The leuco sulfuric acid esters of anthraquinone-azodyestuffs corresponding to the following general formula wherein X standsfor a member of the group consisting of wherein R represents a radical selected from the group consisting of benzene, chlorobenzene, dichlorobenzene, methoxy-benzene, methoxy-chlorobenzene, methylbenzene, methoxy-bromobenzene, dimethoxy-benzene, dimethoxychlorobenzene, methoxy benzoylamino chlorobenzene, methyL-dichlorobenzene, methyl-methoxy bromobenzene and diethoxy-bromobenzene.

. 6 3. The leuco sulfuric acid ester of an anthraquinone- 5. The leuco sullfiuri'c acid ester of an anthraquinoneazo-dyestufi corresponding to the following formula azo-dyestufi corresponding to .the following formula OH: CH: OSO Na OSOzNa 10 5 o co N=N-OH N==N+H 0 oo 0 m '0 H 7 NH 01 soon: 10 OSOiNa I 4. The leuco sulfuric acid ester of an anchraquinone- R eferences Clted 1n the file of th1s patent azo-d estufi eorres ondm to the followm formula y p g OH, g UNITED STATES PATENTS OSOsNa I 1,028,139 Sohmidt et a1 June 4, 1912 I 15 2,347,027 Besler Apr. 18, 1944 2,617,798 Mueller et a1. Nov. 11, 1952 C0 FOREIGN PATENTS G 873,968 France Apr. 13, 1942 OS OaNa 20 

1. THE LEUCO SULFURIC ACID ESTERS OF ANTHRAQUINONE-AZODYESTUFFS CORRESPONDING TO THE FOLLOWING GENERAL FORMULA 